Recently, a significant progress has been made relating to an organic light-emitting device. The characteristic feature of the device includes that high luminance, a variety of emission wavelengths and a high-speed response can be obtained at a low voltage and also a thin and light-weight light-emitting device can be produced. For these reason, application of an organic light-emitting device in a broad and diverse range has been suggested.
At a practical level, however, optical output with more improved luminance or higher conversion efficiency is required. In addition, there are still a lot of problems associated with durability, for example, time-dependent change due to use for a long period of time or degradation due to atmospheric gas including oxygen, moisture or the like. Furthermore, for an application in a full-color display and the like, light emission of red, green, and blue colors with good color purity is required, but it cannot be said that such needs are completely met at the present moment.
In addition, a large number of aromatic compounds and fused ring aromatic compounds have been researched and proposed as a fluorescent organic compound to be used as a constituent material of as an electron transport layer or a light-emitting layer. However, it is hard to say that a compound capable of sufficiently satisfying emission luminance and durability has been obtained.
The case where any such aromatic compound or fused ring aromatic compound is used as a constituent material of an organic light-emitting device is described in, for example, Japanese Patent Application Laid-Open Nos. 2002-8867, H10-330295, and H10-294177. These patent documents also disclose the application of the aromatic compound or the fused ring aromatic compound to an organic light-emitting device.